Material handling system for vibratory mills

ABSTRACT

A material handling system for vibratory finishing or grinding mills into which are placed materials and abrasive media and wherein the materials are operated upon. In a finishing mill the materials are parts which are finished, polished, or deburred, and in a grinding mill the materials usually are chemicals which are reduced in size. The system includes a vibratory mill into which such materials and media are placed, a vibratory screen separator for separating the materials from media after completion of the operation thereon, a hoist pan for handling the media or material and media, and a jib hoist system for moving and positioning the pan. Media or material and media are loaded into the pan, and same is lowered to the top of the finishing machine causing the load to be evenly dumped into the finishing machine. After the finishing operation, the material may be moved or transported in any suitable manner to any further operation stage, and the media is returned to the hoist pan. A pan driving mechanism is provided for rotating the pan as the media is supplied thereto from the separator or mill such that the pan is evenly loaded. Several bottom-dumping pan configurations are disclosed which provide a relatively even discharge of the media into the mill when the pan engages the mill.

United States Patent [191 Strom [4 1 May 14, 1974 MATERIAL HANDLING SYSTEM FOR VIBRATORY MILLS [75] Inventor: John R. Strom, Fullerton, Calif.

[73] Assignee: Sweco Inc., Los Angeles, Calif.

[22] Filed: May 5, 1972 [211 Appl. No.: 253,272

Related US. Application Data [63] Continuation of Ser. No. 825,860, May 19, 1969.

[52] US. Cl 241/171, 51/163, 241/202 [51] Int. Cl. B02c 17/00, B02c 23/02, B24b 31/06 [58] Field of Search 51/7, 163; 214/18 R, 18 G, 214/18 D, 18 V, 28, 32, 741, 317; 241/109, 171, 186, 202, 222, 245, 248, 265, 271, 284,

Primary Examiner-Granville Y. Custer, Jr. Assistant ExaminerGary L. Smith Attorney, Agent, or Firm-Lyon & Lyon 5 7] ABSTRACT A material handling system for vibratory finishing or grinding mills into which are placed materials and abrasive media and wherein the materials are operated upon. In a finishing mill the materials are parts which are finished, polished, or deburred, and in a grinding mill the materials usually are chemicals which are reduced in size. The system includes a vibratory mill into which such materials and media are placed, a vibratory screen separator for separating the materials from 'media after completion of the operation thereon, a hoist pan for handling the media or material and media, and a jib hoist system for moving and positioning the pan. Media or material and media are loaded into the pan, and same is lowered to the top of the finishing machine causing the load to be evenly dumped into the finishing machine. After-the finishing operation, the material may be moved or transported in any suitable manner to any further operation stage, and the media is returned to the hoist pan. A pan driving mechanism is provided for rotating the pan as the media is supplied thereto from the separator or mill such that the pan is evenly loaded. Several bottomdumping pan configurations are disclosed which provide a relatively even discharge of the media into the mill when the pan engages the mill.

14 Claims, 12 Drawing Figures PATWEMAY i4 m4 sum 1 of 4 I NVENTOR JOHN /2. 57/20/14 A7770NEV$ PAJFENEEWY 14 m4 3 8 1 0.585

sum 2 OF 4 INVENTOR JOHN 9. \57/20/14 BY K MATERIAL HANDLING SYSTEM FOR VIBRATORY MILLS both of said applications being assigned to the assignee 5 of the present application.

The present invention relates to vibratory mills and more particularly to a material handling system for such mills.

Although applicable to both finishing and grinding mills, the concepts of the present invention will be described with reference to finishing mills. Various types of finishing mills have been in use for a number of years for finishing, polishing and deburring. An example of the construction of a mill of this type is disclosed in Podmore et al. US. Pat. No. 3,100,088. This type of mill includes an annular bowl into which is loaded parts and abrasive media. Examples of such parts are castings of metal, plastic parts, and so forth. The mill may include a source of vibratory energy such as that described in Meinzer US. Pat. No. 2,284,671.

Conventionally, the media or parts and media are loaded into the mill manually. This has been accomplished through the use of a rectangular media receptacle having an opening at one end and suspended from an overhead hoist. Usually, two men, one holding the front end of the receptacle down while the other pushes the rear end of the receptacle up are necessary in order to redistribute the media load in the pan from a carrying to a pouring position. The mill operator must be present'in order to load the media into the mill, and into the receptacle so as to properly distribute the media load in the receptacle to prevent uneven distribution thereof. It will be readily apparent that there are a number of disadvantages to media handling in this manner, not the least of which is the lack of ability to automate the operational steps required, and the complete reliance upon the adeptness of the men involved. Also, media generally is handled by bucket conveyors from which it is difficult to remove all media when it is desired to change to a different media. Consequently, undesirable mixing of different media can occur.

Accordingly, it is a principal object of this invention to provide a new material handling system for vibratory mills.

Another object of this invention is to provide an improved material handling system employing a substantially round pan for evenly discharging a full load of material into a vibratory mill.

Another object of this invention is to provide an improved material handling system employing a substantially round pan for evenly discharging a full load of material into a vibratory mill. Another object of this invention is to provide an improved material handling system for vibratory finishing mills and which is readily adapted to be partly or substantially automated.

These and other objects and features of this invention will become better understood through a consideration of the following descriptiontaken in conjunction with the drawings in which:

FIG. 1 is a perspective view of a material handling system for vibratory mills according to the present invention;

FIG. 2a is a simplified plan view of a drive arrangement for the round hoist pan used in the system of FIG.

FIGS. 2b and 2c respectively are plan and elevational views of the pan and drive system;

FIG. 3 is a fragmentary view of an end of a stabilizer arm for supporting the hoist pan;

FIGS. 40 through 40 illustrate in more detail an embodiment of a round hoist pan having an opening bottom for dumping material into the vibratory mill;

FIG. 5 is a partial view of another embodiment of a round hoist pan; and

FIGS. 6a through 6c illustrate a further round hoist pan embodiment.

Turning now to the drawings, FIG. 1 illustrates a media handling system for vibratory mills incorporating the concepts of the present invention, and includes a vibratory finishing mill 10 of conventional construction having a toroidal chamber 11 into which parts and abrasive media are placed and vibrated such that the parts are finished, polished, deburred, and so forth. This mill may be, for example, a Model FM-IO mill manufactured by SWECO, Inc., of Los Angel'es, Calif. The abrasive media or, parts and media if desired, is handled by a round hoist pan 12 which is supported, moved and positioned by a stabilizer arm 13 of a jib hoist or bridge crane system 14. The pan 12 is moved and centered above the machine 10 to dump the load within the pan into the bowl 11. After the finishing operation is completed, the parts and media are discharged through a chute 15 onto a vibrating screen separator 16 to separate the parts from the media. If the parts are of a metal susceptible to magnetic attraction, a moving belt magnetic separator 17 may be used to retrieve the parts rather than allowing them to discharge from an end 18 of the separator 16. The separator 16 includes a media discharge chute 19 for allowing the media to be returned to the pan 12 when it is moved to the dotted line position 20 as seen in FIG. 1. The separator 16 is of conventional construction and includes a screen having a mesh size for allowing media to fall therethrough and into discharge chute 19, the mesh size being small enough to retain the parts for movement thereof to the discharge end 18 of the separator 16. Alternatively a mill having its own separating means may be used without requiring the use of a separate separator 16.

As will be described subsequently, a drive system 21 is provided to rotate pan 12 when it is in the position 20 during discharge of the media from the chute 19 to evenly distribute the media in the pan. Rotation of the pan during loading thereof causes the material fed thereto to be evenly distributed therein. Uneven distribution of material would cause the pan to hang unbalanced and create difficulty in transporting, positioning and dumping the pan, and discharge of material into the mill would be uneven. The drive system may be a friction drive such as a type employing a rubber surfaced wheel, but preferably is a magnetic drive system as described subsequently. I

The separator 16 preferably includes different mesh screens such that reusable media can be separated from broken or chipped media, the latter being discharged through a chute (not shown). After the pan 12 has been reloaded with media from the separator 16, it may be suitably stored on-the floor, in a rack, stacked with other pans, or again discharged into the mill with a new load of parts. Additionally, the reloaded pan may be discharged into another mill of the nature of the mill 10 by the jib hoist system 14, or by another hoist system such as a bridge crane system. Another pan with a different size or type media may be picked up by the jib hoist system 14 and used with the mill 10. Thus, it will be apparent that various combination pans, media types and sizes, mills, and so forth may be incorporated into the system of FIG. 1.

Turning now to a more detailed discussion of the apparatus illustrated in FIG. 1, the finishing mill 10, as noted earlier, is a conventional unit. This mill 10 includes a base 25 from which is supported a bowl 11 by resilient members, such as springs (not shown). A vibratory source is mounted within the mill and coupled with the bowl to vibrate the same. The bowl includes a center column 26 which has been modified to include a cover 27 having a projection 28. The projection, as will be described subsequently, serves to open the bottom of the pan 12 to cause discharge of the material contained therein evenly into and around the interior of the bowl 11.

The jib hoist system 14 includes a stationary base 30 which is free standing or affixed to any suitable manner to the base 25 of the mill, such as by a pair of plates welded to both bases, or affixed to the separator base. The base 30 is provided with a vertical pivot or king pin 31 which supports a vertical column member 32 of the crane for rotation to allow proper positioning of the pan 12. A horizontal beam 33 is affixed to the upper end of the member 32 to support a hoist or winch 34 by means of a hook 35. A counterbalance 36 may be provided. A chain 37 is coupled between the winch 34 and a support bracket 38 on the outer end of the stabilizer arm 13. The bottom 39 of the bracket 38 has slot 40 therein perpendicular (note FIG. 1) or angled (note FIG. 3) with respect to the arm 13 for receiving and supporting the pan 12 as will be described subsequently. The inner end of the arm 13 is coupled to a pair of flange members 43 and 44 which are coupled together by a pair of plates and encircle the support member 32. Rollers are provided on the inner sides (note FIG. 2b) of these flange members to allow the stabilizer arm to roll up and down the member 32 as the winch 34 is operated. A handle 45 is provided for rotating the hoist system about the pivot 31 to allow the pan 12 to be moved to above the mill 10 or to another closely adjacent mill, to be moved to the dotted line position 20 for reloading the pan with media, or for moving the pan to another position where it may be stored, stacked, or the like. The pan has a diameter slightly smaller than the inside diameter of the bowl 1 l.

The vibrating screen separator 16 may be a. conventional unit including a base 50 which may be affixed to the base 25 of the mill, and a screening chamber 51. The screening chamber includes one or more screens and is vibrated by means of a motor and vibratory drive system 52. The screening chamber may include an upper coarse mesh screen for enabling the parts to be separated from the media, and a lower fine mesh screen Considering now the drive system 21 as more completely illustrated in FIGS. 2a through 20, the same includes an electrical motor 60 coupled by a chain 61 to a magnetic roller or rollers 62. An idler 63 maintains proper tension of the chain 61. One or more of the rollers 62 may be provided, and a typical roller is 4 inches in diameter. A metal wheel or pulley may be mounted on the motor shaft and directly contact and drive the rollers 62 thereby obviating the need for a chain drive 61. This driveassembly may be mounted to the overall system in one of several ways. As illustrated inFlGS. 1 and 2a, a support bracket 64 may be affixed to the base of the separator 16, or alternatively, .may be affixed to the base 30 of the crane or to the base 25 of the mill. A channel member 65 as best seen in FIG. 2a is affixed to the bracket 64, and has extending therefrom a pair of bracket plates 66 and 67. These bracket plates may in turn pivotally support a pair of bracket arms 68 and 69 for supporting the motor 60 and roller 62 at a pivot 70. A spring 71 is coupled between the arm 69 and the bracket 64, and stop plates 72 and 73 are respectively affixed to the arm 69 and bracket 64 for aiding in release of the pan from the magnetic drive as will be described subsequently.

The magnetic roller or rollers 62 serve two purposes. As the round pan 12 is moved into position, the roller pulls the pan into engagement therewith, and drives the pan. Typically, the pan is driven at a speed of IS to 20 revolutions per minute to enable uniform distribution of the media into the pan from the separator. As the pan is being loaded, there is a tendency for the first gush of media to move the pan off center and away from the driving roller 62, but this is overcome by the magnetic attraction of the roller. Additionally, prob lems of friction and pressure in driving the pan are eliminated by the use of the magnetic drive. The pan may be separated from the roller by moving the pan backward (clockwise about the pivot thereby extending the retention spring, and then pulling the pan forward briskly until the stop plates 72 and 73 engage such that the momentum of the pan snaps it away from the roller. If desired, discharge of parts or parts/media may be made directly from the finishing mill into the pan by physically rearranging the drive arrangement such that the pan is properly positioned with respect to the mill for receiving the material therefrom.

FIGS. 2b and 2c illustrate an alternative arrangement for mounting the drive assembly 21 wherein the channel member 65 thereof is pivotally secured to the stabilizer arm 13. The drive assembly may be biased clock wise as viewed in FIG. 2b by suitable means, such as a spring (not shown) to maintain the rollers 62 against the periphery of the pan 12. In the arrangement of FIGS. 2b-2c, the bracket arms 68 and 69 are affixed directly to the channel member 64. It will be apparent that the rollers 62 illustrated in FIGS. 1 and 2 are journalled for rotation by suitable hearings or bushings.

As noted earlier, the support bracket 38 of the stabilizer arm 13 has a slot 40 in the bottom thereof. This slot may have the configuration illustrated in FIGS. 2b and 3 wherein it flares outwardly at to enable the support stud 76 (note FIG. 2c) and flange 77 of the pan to be guided into engagement with the arm 13. The bracket may be in the form of a box as shown in FIG. 1, or may be open as shown in FIGS. 2b, 2c and 3 with sides 78 and 79 and inclined faces 80 and 81 to guide and receive the flange 77.

FIG. 2b illustrates a flange 77 of one diameter for one size pan, and illustrates the manner in which the flange and support stud 76 may be positioned in the support bracket 38 at the center line of the stabilizer arm 13. FIG. 3 illustrates the manner in which another size pan having a larger flange 82 is supported and retained slightly off center. This support configuration enables different diameter pans to be rotated by the magnetic drive arrangement. The chain 37 from the winch 34 may be directly coupled with a hook 84 of the pan, or alternatively, may be coupled near the outer end of the arm 13.

FIGS. 2b and 2c also illustrate in greater detail the manner in which the flanges 43 and 44 of the arm 13 are coupled together by means of plates and 91 and include pairs of upper and lower rollers, only the upper rollers 92 and 93 being seen in the drawings. These rollers bear against the faces of the column member 32 to allow the stabilizer arm 13 to freely move up and down the member 32 as described earlier. Additionally, a base plate 95 may be provided for supporting the base 30 of the jib crane, and may also have secured thereto the bases of the finishing mill and separator if desired.

Turning now to a consideration of the specific embodiments of the round hoist pan 12, FIGS. 40 through 4c illustrate a pan 99 which includes a latching-type bottom 100 which is unlatched and caused to open as the bottom of the pan engages the top of the mill 10. This pan includes a cylindrical housing or wall 101 with a bottom flange 102, and a frusto-conical insert 103 secured to the housing and flange. A central cone 104 is provided and is secured at the top thereof by a plurality of rods 105 extending to the interior wall of the body 101, and near the bottom thereof by a plurality of rods 106 extending to the insert 103. The bottom 100 of the pan 99 comprises a pair of semicircular bottom segments 107 and 108 which are hinged together by a pin 108 which extends through the bottom of the central cone 104. A flange 110 may be secured at the top of the housing 101 to reinforce the housing.

The bottom segments 107 and 108 are maintained in their normally closed position by a pair of latch mechanisms, only the left hand mechanism being shown for simplicity of illustration. Each latch mechanism includes a bolt 112 which releasably engages a bracket 113 affixed to the respective bottom segment. The bolt is coupled to a release arm 114 which is pivoted at 115 by a pair of brackets 116 and 117. As the bottom 118 of the arm 114 engages a cam face 1199 mounted at the top of the mill 10, the bolt 112 is pulled from the bracket 113 allowing the respective bottom segment to lower as illustrated in dashed lines in FIG. 4a. The arm 114 is normally biased to close the bolt 112 with the bracket 113 by means ofa spring 121, and a spring 122 is provided to return the bottom segments 107 and 108 to their closed positions after the media has been dumped from the pan 99. Latching mechanisms as just described are provided for both of the bottom segments 107 and 108. It further will be apparent that the construction of the pan 100 dumps the media in a substantially annular pattern into the interior of the bowl ll of the mill 10 to provide a relatively even distribution of the media around the bowl. No particular configuration is required at the top of the center column 29 to cause dumping of this pan embodiment.

FIG. 5 illustrates another round pan construction including a cylindrical housing 130, a conical insert 131 and a pair of semi-circular bottom segments or doors 132 and 133. The central stud 76 extends down into the pan and is coupled with the top of a cone 134. A central flange 135 is affixed to the inner wall of the housing 130 by means of a plurality of radially extending rods 136. A ball thrust bearing 137 is provided, and FIG. 5 shows the configuration thereof which is also used with the pan of FIG. 4a. The bottom segments 132 and 133 are hinged by a pin 138 in a manner similar to the bottom segments 107 and 108 in FIGS. 4a-4b; however, the hinge pin 138 is not coupled with the cone 134, and the bottom segments 132 and 133 are free to move up and down with respect to the cone 134. Additionally, a pair of arcuate guides 139 and 140 are coupled at the inner circular edges of the respective bottom segments 132 and 133. When the cone 134 is in its lower posi tion, the central portions of the bottom segments 132 and 133 are supported thereon and the outer edges are supported on the insert 131, and these segments assume the closed (full-lined) position. The weight of the media on the segments maintains the bottom of the pan closed. The lower end of the stud 76 extends into a cylindrical guide 141 in the cone 134, and the stud and cone are coupled together with a pin 142. The pin 142 rides in a slot 143 in the guide. In this manner the cone may move freely up and down on the stud 76.

As the pan is lowered to the mill, the bottom of the cone 134 engages the cover 27 of the center column of the mill 10 thereby preventing the cone 134 from lowering further, while allowing the body 130 to lower to the dashed lined position as seen in FIG. 5. This action allows the central portions of the bottom segments 132 and 133 at the guides 139 and 140 to rise up with respect to the cone 134 because of the moment caused by the weight of the media at the outer edges of the segments 132 and 133 causing the segments to fold, thereby providing a substantially annular aperture 144 at the bottom of the pan for discharge of media. After the media is discharged, the pan is raised thereby allowing the cone to move down and the bottom segments to again assume the flat closed position. If necessary, the bottom segments may be closed manually.

Alternatively, the center column may include a remotely actuated mechanism, such as an air cylinder and piston, which can be operated to extend upwardly and engage the actuator of the pan. With this arrangement, the pan is merely lowered to above the mill and does not have to be lowered into engagement with the cover 27.

FIGS. 6a through 60 illustrate another configuration of a round hoist pan providing an annular discharge of media. This pan includes a housing having a conical insert 151 affixed thereto, and a moving conical bottom 152. The pan is supported by means of a central bracket 153 which is secured to the housing 150 by radially extending rods 154. A ball thrust bearing 155 is provided for the supppot stud 76, and the same type of bearing is used with the pan of FIGS. 4a and 5. A central support column 157 is rigidly secured to the interior wall of the insert 152- by means of rods 158. The movable bottom 152 is affixed to a central cap 159 which in turn is secured to a stud 160 which extends through the column 157. A spring 161 is provided on the stud and is retained by means of an actuator 162 and nut 163. The spring 161 serves to normally bias the actuator 162 and stud 160, and thus the bottom 152, downwardly to the full-lined position shown in FIG. 6a. When the actuator 162 engages the cover of the center column of the mill, the bottom 152 is raised to the dashed-line position shown in FIG. 6a to provide an annular aperature 165 for discharge of media evenly into the bowl of the finishing mill. The bottom of the actuator 162 is above the bottom of the pan thus enabling the pan to be placed on a floor for storage or loading without causing the bottom 152 to open. With each of the pans disclosed herein, resilient gaskets may be used at the edges of the movable bottoms to provide a good seal with the interior sides of pans.

it will be apparent that the present invention provides a new and novel material handling system for vibratory mills wherein media or parts and media may be handled in a relatively simple, positive and efficient manner, and may be evenly discharged into the finishing mill. The system further enables the parts and media to be separated and the media to be returned to the pan for subsequent storage and reuse. The present'invention also provides a relatively simple construction for a round hoist pan which can pump material contained therein into the finishing mill in a relatively evenly distributed manner. Furthermore, the system of the present invention may be relatively easily automated through the use of suitable controls and limit switches for sensing and controlling the movement and positioning of the hoist pan.

As noted earlier, the concepts of the present invention also are applicable to grinding mills wherein material, such as chemical compounds, paint pigments, and so forth, and media are loaded into the mill to grind the material, or otherwise reduce the material in size.

What is claimed is:

l. A material handling system for mills comprising a mill having a chamber for receiving media and material whereby the material may be operated upon within the chamber,

first conveying means to convey said media and material from said chamber,

separating means for receiving media and material from said first conveying means and for separating the material from the media and providing the media to an outlet; hoist pan means for receiving, transporting and dis charging a load of media, said hoist pan means comprising a pan having a movable bottom responsive to. movement of said pan in predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the media therefrom into the chamber of said mill, and

means for supporting said hoist pan means and moving the same to receive said media from said separating means and for moving said pan means directly above said mill to enable the contents of said pan means to be discharged into the chamber of said mill.

2. A system as in claim 1 wherein said hoist pan means comprises a cylindrical housing having a bottom comprising a pair of hinged bottom segment members,

means coupled with said housing and said bottom for supporting said housing and said bottom, and

latch means coupled with said segment members for allowing said segment members to open and dump media from said pan means into said mill upon movement of said pan into predetermined proximity with said mill.

3. A system as in claim 2 wherein said latch means comprises a pair of latches respectively coupled with a pair of bottom segments, and includes operator arms for operating said latches, and means on said mill for engaging said operator arms to release said latches and thereby allow said bottom segments to open and discharge media from said pan means.

4. A system as in claim 1 wherein said hoist pan means comprises a cylindrical housing having a bottom comprising a pair of hinged segment members, said housing having means near the bottom thereof for supporting the edges of said hinged segment members, and

retaining means coupled with said housing and said bottom for supporting said housing and said segment members.

5. A system as in claim 4 wherein said retaining means coupled with said housing and said bottom comprises a support member affixed to said housing and a central movable core member tapering inwardly from the bottom thereof toward the top thereof for supporting the central section of said hinged segment members, said mill having a central column member adapted to be engaged by the bottom of said coremember upon lowering of said pan means onto said mill.

6. A material handling system for mills comprising a mili having a substantially circular chamber for receiving parts and media whereby the parts may be finished, polished or deburred,

first conveying means to convey said parts and media from said chamber to a separating means,

separating means for receiving parts and media from said first conveying means and for separating the parts from the media and providing the media to an outlet.

hoist pan means for receiving, transporting and evenly discharging a load of media into said chamber, said hoist pan means comprising a substantially circular pan having a movable bottom and being responsive to engagement of said pan with said mill for discharging said media into said chamber, and

means for supporting and moving said hoist pan means and for positioning s'aid pan means substantially centrally over and above the chamber of said mill.

7. A material handling system for mills comprising a mill having a circular chamber for receiving material to be operated upon within said chamber,

first conveying means to convey said material for said chamber to a separating means,

separating means for receiving material from said first conveying means and for separating one portion of said material from another portion of said material and providing the material to an outlet,

pan means for receiving, transporting and evenly discharging a load of material into said chamber, said pan means comprising a substantially circular pan having a movable bottom responsive to movement of said pan into predetermined proximity directly above said mill for discharging said material into said chamber, and

means for supporting and moving said pan means-and for positioning said pan means substantially centrally over and above the chamber of said mill.

8. A system as in claim 7 wherein said material includes media for grinding, finishing, or the like, and means are provided for rotating said pan during loading thereof with media to enable even distribution of the media therein.

9. A material handling system for mills comprising a mill having a circular chamber for receiving material to be operated upon within said chamber,

conveying means to convey at least a portion of said material from said chamber to a pan means,

pan means for receiving, transporting and discharging a load of material into said chamber, said pan means comprising a pan having a movable bottom responsive to positioning of said pan in predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material from said pin into the chamber of said mill, and

means for supporting said pan means and moving the same to receive certain constituents of said material after use thereof in said mill, and for moving said pan means directly above said mill to enable the contents of said pan means to be discharged into the chamber of said mill.

10. A material handling system for mills comprising a mill having a chamber for receiving material within which the material may be operated upon,

hoist pan means for receiving, transporting and discharging a load of material, said hoist pan means comprising a pan having a movable bottom responsive to movement of said pan in predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material therefrom into the chamber of said mill, and

means for supporting said hoist pan means and moving the same to receive said material from a source of said material and for moving said pan means directly above said mill to enable the contents of said' pan means to be discharged into the chamber of said mill. 11. A material handling system for mills comprising a'mill having a chamber for receiving material within which the material may be operated upon, and means for conveying material from said chamber,

hoist pan means for receiving, transporting and discharging a load of material, said hoist pan means comprising a pan having a movable bottom responsive to movement of said pan into predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material therefrom into the chamber of said mill, and

second means for supporting and moving said hoist pan means and for positioning said pan means substantially centrally over and above the chamber of said mill.

12. A material handling system for vibratory mills comprising a vibratory mill having a substantially circular chamber for receiving parts and media and within which the parts may be finished, polished, deburred, or

the like, and said mill including pan operating means,

hoist pan means for receiving, transporting and evenly discharging a load of media into said chamber, said hoist pan means comprising a substantially circular pan having a movable bottom and being responsive to engagement of said pan with said pan operating means for discharging said media into said chamber in a substantially evenly distributed manner, and

means for supporting and moving said hoist pan means=and for positioning said pan means substantially centrally over and above the chamber of said mill.

13. A material handling system for mills comprising a mill having a chamber for receiving material within which the material may be operated upon, and means for conveying material from said chamber, said material including media for grinding, finishing, or the like,

separating means for receiving material and separating media therefrom, v

hoist pan means for receiving, transporting and discharging a load of material, said hoist pan means comprising a pan having a movable bottom reponsive to movement of said pan into predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material therefrom into the chamber of said mill, and

means for supporting and moving said hoist pan means and for positioning said pan means substantially centrally over and above the chamber of said mill.

14. A material handling system as in claim 13 wherein said separating means is positioned adjacent said mill for receiving material conveyed from said chamber of said mill. 

1. A material handling system for mills comprising a mill having a chamber for receiving media and material whereby the material may be operated upon within the chamber, first conveying means to convey said media and material from said chamber, separating means for receiving media and material from said first conveying means and for separating the material from the media and providing the media to an outlet, hoist pan means for receiving, transporting and discharging a load of media, said hoist pan means comprising a pan having a movable bottom responsive to movement of said pan in predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the media therefrom into the chamber of said mill, and means for supporting said hoist pan means and moving the same to receive said media from said separating means and for moving said pan means directly above said mill to enable the contents of said pan means to be discharged into the chamber of said mill.
 2. A system as in claim 1 wherein said hoist pan means comprises a cylindrical housing having a bottom comprising a pair of hinged bottom segment members, means coupled with said housing and said bottom for supporting said housing and said bottom, and latch means coupled with said segment members for allowing said segment members to open and dump media from said pan means into said mill upon movement of said pan into predetermined proximity with said mill.
 3. A system as in claim 2 wherein said latch means comprises a pair of latches respectively coupled with a pair of bottom segments, and includes operator arms for operating said latches, and means on said mill for engaging said operator arms to release said latches and thereby allow said bottom segments to open and discharge media from said pan means.
 4. A system as in claim 1 wherein said hoist pan means comprises a cylindrical housing having a bottom comprising a pair of hinged segment members, said housing having means near the bottom thereof for supporting the edges of said hinged segment members, and retaining means coupled with said housing and said bottom for supporting said housing and said segment members.
 5. A system as in claim 4 wherein said retaining means coupled with said housing and said bottom comprises a support member affixed to said housing and a central movable core member tapering inwardly from the bottom thereof toward the top thereof for supporting the central section of said hinged segment members, said mill having a central column member adapted to be engaged by the bottom of said core membEr upon lowering of said pan means onto said mill.
 6. A material handling system for mills comprising a mill having a substantially circular chamber for receiving parts and media whereby the parts may be finished, polished or deburred, first conveying means to convey said parts and media from said chamber to a separating means, separating means for receiving parts and media from said first conveying means and for separating the parts from the media and providing the media to an outlet. hoist pan means for receiving, transporting and evenly discharging a load of media into said chamber, said hoist pan means comprising a substantially circular pan having a movable bottom and being responsive to engagement of said pan with said mill for discharging said media into said chamber, and means for supporting and moving said hoist pan means and for positioning said pan means substantially centrally over and above the chamber of said mill.
 7. A material handling system for mills comprising a mill having a circular chamber for receiving material to be operated upon within said chamber, first conveying means to convey said material for said chamber to a separating means, separating means for receiving material from said first conveying means and for separating one portion of said material from another portion of said material and providing the material to an outlet, pan means for receiving, transporting and evenly discharging a load of material into said chamber, said pan means comprising a substantially circular pan having a movable bottom responsive to movement of said pan into predetermined proximity directly above said mill for discharging said material into said chamber, and means for supporting and moving said pan means and for positioning said pan means substantially centrally over and above the chamber of said mill.
 8. A system as in claim 7 wherein said material includes media for grinding, finishing, or the like, and means are provided for rotating said pan during loading thereof with media to enable even distribution of the media therein.
 9. A material handling system for mills comprising a mill having a circular chamber for receiving material to be operated upon within said chamber, conveying means to convey at least a portion of said material from said chamber to a pan means, pan means for receiving, transporting and discharging a load of material into said chamber, said pan means comprising a pan having a movable bottom responsive to positioning of said pan in predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material from said pin into the chamber of said mill, and means for supporting said pan means and moving the same to receive certain constituents of said material after use thereof in said mill, and for moving said pan means directly above said mill to enable the contents of said pan means to be discharged into the chamber of said mill.
 10. A material handling system for mills comprising a mill having a chamber for receiving material within which the material may be operated upon, hoist pan means for receiving, transporting and discharging a load of material, said hoist pan means comprising a pan having a movable bottom responsive to movement of said pan in predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material therefrom into the chamber of said mill, and means for supporting said hoist pan means and moving the same to receive said material from a source of said material and for moving said pan means directly above said mill to enable the contents of said pan means to be discharged into the chamber of said mill.
 11. A material handling system for mills comprising a mill having a chamber for receiving material within which the material may be operated upon, and means for conveying material from said chamber, hoist pan means for Receiving, transporting and discharging a load of material, said hoist pan means comprising a pan having a movable bottom responsive to movement of said pan into predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material therefrom into the chamber of said mill, and second means for supporting and moving said hoist pan means and for positioning said pan means substantially centrally over and above the chamber of said mill.
 12. A material handling system for vibratory mills comprising a vibratory mill having a substantially circular chamber for receiving parts and media and within which the parts may be finished, polished, deburred, or the like, and said mill including pan operating means, hoist pan means for receiving, transporting and evenly discharging a load of media into said chamber, said hoist pan means comprising a substantially circular pan having a movable bottom and being responsive to engagement of said pan with said pan operating means for discharging said media into said chamber in a substantially evenly distributed manner, and means for supporting and moving said hoist pan means and for positioning said pan means substantially centrally over and above the chamber of said mill.
 13. A material handling system for mills comprising a mill having a chamber for receiving material within which the material may be operated upon, and means for conveying material from said chamber, said material including media for grinding, finishing, or the like, separating means for receiving material and separating media therefrom, hoist pan means for receiving, transporting and discharging a load of material, said hoist pan means comprising a pan having a movable bottom reponsive to movement of said pan into predetermined proximity directly above said mill for releasing in a substantially evenly distributed manner the material therefrom into the chamber of said mill, and means for supporting and moving said hoist pan means and for positioning said pan means substantially centrally over and above the chamber of said mill.
 14. A material handling system as in claim 13 wherein said separating means is positioned adjacent said mill for receiving material conveyed from said chamber of said mill. 